$4$. will have to
$5$. doesn't rain
$6$. lived
$7$. wouldn't mind
$8$ was
$9$. left
$10$. had - would buy
$11$. would have been
$12$. would have forgotten
`->`Câu đk loại `1`: If + S + V(s/es), S + will/can + V-inf
`->`Câu đk loại `2`: If + S + Ved/2, S + would/could + V-inf
`->`Câu đk loại `3`: If + S + had + Ved/3, S + would have + Ved/3